Target-detection device for a missile system

ABSTRACT

The invention relates to a target-detection and target-alignment device for a missile system whose field of view is expanded by a wide-angle lens system, which does not contain any optical components which must be additionally moved, and which is equipped with an integrated system for correction of homogeneity of the ambient conditions. Two radiometers or photometers are connected to two emission surfaces positioned on opposite sides of the image of the field of view to adjust the angle of the target detector to compensate for mismatch of the output signals of the emission surfaces.

FIELD OF THE INVENTION

The invention relates to a target-detection device for a missile systemsuch as a shoulder launched missile system.

The invention relates, in particular, to such a missile detection systemin which an imaging sensor of a target detector on the missile sends animage to a wide angle lens system.

BACKGROUND

Modern operator controlled missile systems, such as shoulder launchedmissile systems are generally aimed at a target by the operator by meansof optical devices containing simple or complex reflective elements.Detection and assignment of the target in such cases is achieved eitherin a simple way by observers with binoculars or by guidance systems,which receive their information from sensors which are not part of themissile or its launching system.

Also known are IR thermal imaging systems for target acquisition by anobserver (without self-guidance by the missile system) for example, byusing the imaging sensor of the missile itself for the imaging of thetarget. In such embodiments, the imaging missile sensor is used fortarget detection and acquisition in combination with a wide-angle lensadapter, in order to broaden the normally narrow visual field providedby the imaging sensor on the missile.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a thermal imagingsystem of the above type in which the wide-angle visual field of thewide-angle adapter is adjusted without any movable optical components tocorrect for non-uniform ambient conditions.

This object is achieved according to the invention by providingradiation detection means for detecting ambient atmospheric conditionsand for adjusting emissions on both sides of the emission image producedby the wide-angle adapter to compensate for non-uniformity in theambient atmosphere.

In further accordance with the invention, the radiation detection meanscomprises radiation sensors for detecting radiation differences in theambient atmosphere, for example, by aiming one radiation sensor towardsthe sky and another radiation sensor towards the ground and supplyingemission from the radiation sensors to two auxiliary emission membershaving emission surfaces located on opposite sides of an optical memberwhich produces the image in the wide-angle lens system.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a diagrammatic illustration of an embodiment of the invention.

FIG. 2 is a sectional view taken on line 2—2 in FIG. 1.

DETAILED DESCRIPTION

Referring to the drawing, therein is shown a missile 10, for example, ashoulder launched missile, having a target seeker head 14. The seekerhead 14 has an imaging system which receives an image in front of themissile 10 and transmits the image along an optical axis 16 obliquelyinclined with respect to an axis 12 of the missile. The seeker head ismounted for swiveling movement but during imaging it is locked in place.Mounted on a missile launcher 11 of the weapon system is a mirror orprism system 15. The image transmitted along optical axis 16 from targetseeker head 14 falls on the center of an a focal lens system 17, whichin, conventional manner, widens the visual field of the image from thetarget seeker head, the lens system 17 being disposed on an optical axis18 which is substantially parallel to missile axis 12.

The image thus formed is fed to an appropriate signal-transmissionsystem 19, 20 and in turn to a monitor 13 or similar display devicewhich can be viewed by an operator. The monitor 13 shows the operatorthe target and a mark and the operator aligns the target with the mark,whereupon the target seeker head swivels toward the mark automaticallyor under manual control of the operator so that head 14 locks onto thetarget.

The device described hereinabove is so designed that the image of thetarget seeker head 14 without adaptor lens 15 as well as the lock-onoperation itself can be simultaneously observed by the operator on themonitor 13.

In a particular embodiment, it is possible to achieve the aforesaidoperation semiautomatically or fully automatically by means of anelectronic image-processing system.

Since the target seeker head 14 of the described type often requirescorrection for lack of homogeneity (non-uniformity) of the ambientatmosphere, the invention provides auxiliary surfaces 21 a, 21 b withwell-defined emission for compensating for non-homogeneity. In mostcases, two such surfaces 21 a, 21 b are sufficient and they are disposednext to the mirror or prism 15 a of the mirror or prism system 15 onopposite sides thereof. Optical axis 12 of head 14 is then alignedtaking into account these auxiliary surfaces 21 a, 21 b, in order toachieve the desired homogeneity correction. Adjustment of the emissionof auxiliary surfaces 21 a, 21 b with respect to the ambient conditionsis performed advantageously according to the output signals of one ormore radiation sensors 21, such as radiometers or photometers, whichreceive the ambient radiation. In order to maximize differences ofambient radiation, at least one of the sensors 21 is aimed at the groundand another at the sky.

Although the invention is disclosed with reference to particularembodiments thereof, it will become apparent to those skilled in the artthat numerous modifications and variations can be made which will fallwithin the scope and spirit of the invention as defined by the attachedclaims.

What is claimed is:
 1. A target detection device for a missile systemcomprising: an adjustable target seeker head mounted on a missile, saidtarget seeker head including an imaging sensor producing an image of atarget along an axis disposed obliquely with respect to an axis of themissile, a wide angle lens system including an afocal lens systempositioned to receive the image from the target seeker head to produce awide angle image thereof, said afocal lens system having an optical axissubstantially parallel to the axis of the missile, an external monitorfor target marking and tracking, a signal transmission system connectedto the target seeker head to transmit to the monitor said wide angleimage, radiation sensor means for sensing ambient radiation, and twoauxiliary surfaces adjacent to and on opposite sides of said a focallens system, said auxiliary emission surfaces receiving radiationsignals from said radiation sensor means to correct non-uniformity ofambient radiation.
 2. A device as claimed in claim 1, wherein said wideangle lens system includes a mirror or prism and said auxiliary surfacesare fixed on opposite sides of said mirror or prism.
 3. A device asclaimed in claim 1, wherein said signal transmission system produces onsaid monitor the image produced by the target seeker head without wideangle image enhancement simultaneously with said wide angle image.
 4. Adevice as claimed in claim 1, wherein said missile system includes amissile launcher, said wide angle lens system being secured to saidlauncher.
 5. A device as claimed in claim 1, wherein said radiationsensor means comprises two radiometers or photometers, one of which isaimed upward to the sky and the other of which is aimed downward to theground.